Study on deformation measurement method based on structured light point clouds

基于结构光点云的变形测量方法研究

¹ School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China
² China Academy of Aerospace Aerodynamics, Beijing 100074, China
³ College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China

Received: 13 May 2022

Abstract

For the requirement of structural deformation measurement, a deformation measurement method based on structured light point clouds is proposed. A structured light measurement system is built, and the calibration process based on the assumption of the projector's reverse camera and with the help of the checkerboard calibration board is completed. The pattern projected by the projector is designed by using a four-step phase-shift technique assisted by Gray code. By combining with system parameters which have been calibrated, the three-dimensional reconstruction of the object surface is completed. A structural deformation measurement method based on the statistical analysis of the distance between point clouds is proposed, and the principles of three points cloud distance calculation methods including point-to-point, point-to-surface and surface-to-surface are analyzed. The feasibility and accuracy of the deformation measurement method based on the structured light point cloud proposed in this paper are verified via experiments. Experimental results show that this method can achieve out-plane high-precision displacement measurement of structures.

摘要

针对结构变形测量需求, 提出一种基于结构光点云的变形测量方法。搭建了结构光相机测量系统, 基于投影仪逆向相机的假设并借助棋盘格标定板完成了系统标定。采用格雷码辅助的四步相移技术设计投影仪投射的图案, 并利用标定的系统参数, 完成待测物表面的三维重建, 获得结构表面点云。提出基于点云间距离计算结果的结构变形分析方法, 并分析比较了基于点到点、点到面和面到面3种点云距离计算方法原理。通过实验验证了所提基于结构光点云的变形测量方法的可行性和精度, 实验结果表明, 该方法可以实现结构离面位移的高精度测量。